I kill 2 witches that can summon fist since their summon is annoying( it take away space), also i have Deen, saber, Kliff, Kamui and Malthida to block eyes from getting near the rest of the team, summon witches are too weak for them but thoes eyes is diffirent
I have Delthea as main damage (she have >30 atk)
I use warp ( Tatiana or Slique) to get Delthea near Duma >> attack >> use rescue ( Faye) to get her back >> repeat till Alm can ohko Duma ( warp + rescue is really broken)
Delthea cant stand against Duma, his hit rate is terrible but you cant trust them, i have to use Mila's turnweel several times
also, Duma move when you attack him ( or near him? i dont remember right)